import { describe, it, expect, vi, beforeEach } from "vitest";
import { DocumentIntelligenceAdapter } from "@/src/adapters/document-intelligence-adapter";

function jsonResponse(body: unknown, opts: { status?: number; headers?: Record<string, string> } = {}) {
  return {
    ok: (opts.status ?? 200) < 400,
    status: opts.status ?? 200,
    headers: { get: (k: string) => (opts.headers ?? {})[k] ?? null },
    json: async () => body,
    text: async () => JSON.stringify(body),
  } as unknown as Response;
}

describe("DocumentIntelligenceAdapter", () => {
  beforeEach(() => {
    vi.restoreAllMocks();
  });

  it("isConfigured requires endpoint + apiKey", () => {
    expect(DocumentIntelligenceAdapter.isConfigured({ endpoint: "https://x", apiKey: "k" })).toBe(true);
    expect(DocumentIntelligenceAdapter.isConfigured({ endpoint: "https://x" })).toBe(false);
    expect(DocumentIntelligenceAdapter.isConfigured({})).toBe(false);
  });

  it("normalizes structured + array fields and never fabricates a missing value", async () => {
    const fetchMock = vi.fn(async (url: string) => {
      if (url.includes(":analyze")) {
        return jsonResponse({}, { status: 202, headers: { "operation-location": "https://di.example.com/op/123" } });
      }
      if (url.includes("/op/123")) {
        return jsonResponse({
          status: "succeeded",
          analyzeResult: {
            content: "raw extracted text",
            pages: [{}, {}],
            documents: [
              {
                confidence: 0.93,
                fields: {
                  VendorName: { type: "string", valueString: "Acme AB", confidence: 0.98 },
                  InvoiceTotal: { type: "currency", valueCurrency: { amount: 1234.5, currencyCode: "SEK" }, confidence: 0.91 },
                  // Field region detected but no value could be read — must stay blank, not fabricated.
                  DueDate: { type: "date", confidence: 0.4 },
                  Items: {
                    type: "array",
                    valueArray: [
                      {
                        type: "object",
                        valueObject: {
                          Description: { type: "string", valueString: "Widget", confidence: 0.9 },
                          Amount: { type: "currency", valueCurrency: { amount: 100 }, confidence: 0.85 },
                          Unit: { type: "string", confidence: 0.2 }, // present but empty -> found:false
                        },
                      },
                    ],
                  },
                },
              },
            ],
          },
        });
      }
      throw new Error(`unexpected fetch: ${url}`);
    });
    vi.stubGlobal("fetch", fetchMock);

    const adapter = new DocumentIntelligenceAdapter({ endpoint: "https://di.example.com", apiKey: "key123", pollIntervalMs: 1 });
    const result = await adapter.analyzeDocument(Buffer.from("%PDF-1.4"), "prebuilt-invoice");

    expect(result.modelId).toBe("prebuilt-invoice");
    expect(result.content).toBe("raw extracted text");
    expect(result.documentConfidence).toBe(0.93);
    expect(result.pageCount).toBe(2);

    expect(result.fields.VendorName).toEqual({ value: "Acme AB", confidence: 0.98, found: true });
    expect(result.fields.InvoiceTotal).toEqual({ value: 1234.5, confidence: 0.91, found: true });
    // Not fabricated: value stays null, but DI's own (low) confidence is still recorded.
    expect(result.fields.DueDate).toEqual({ value: null, confidence: 0.4, found: false });

    expect(result.arrayFields.Items).toHaveLength(1);
    expect(result.arrayFields.Items[0].Description).toEqual({ value: "Widget", confidence: 0.9, found: true });
    expect(result.arrayFields.Items[0].Amount).toEqual({ value: 100, confidence: 0.85, found: true });
    expect(result.arrayFields.Items[0].Unit).toEqual({ value: null, confidence: 0.2, found: false });
  });

  it("retries once on 429 then proceeds", async () => {
    let analyzeAttempts = 0;
    const fetchMock = vi.fn(async (url: string) => {
      if (url.includes(":analyze")) {
        analyzeAttempts++;
        if (analyzeAttempts === 1) return jsonResponse({}, { status: 429 });
        return jsonResponse({}, { status: 202, headers: { "operation-location": "https://di.example.com/op/retry" } });
      }
      if (url.includes("/op/retry")) {
        return jsonResponse({ status: "succeeded", analyzeResult: { documents: [{ fields: {} }] } });
      }
      throw new Error(`unexpected fetch: ${url}`);
    });
    vi.stubGlobal("fetch", fetchMock);

    const adapter = new DocumentIntelligenceAdapter({
      endpoint: "https://di.example.com",
      apiKey: "key123",
      pollIntervalMs: 1,
      rateLimitRetryMs: 1,
    });
    const result = await adapter.analyzeDocument(Buffer.from("x"), "prebuilt-receipt");
    expect(analyzeAttempts).toBe(2);
    expect(result.fields).toEqual({});
  });

  it("throws (never returns a fabricated result) when analyze status is failed", async () => {
    const fetchMock = vi.fn(async (url: string) => {
      if (url.includes(":analyze")) {
        return jsonResponse({}, { status: 202, headers: { "operation-location": "https://di.example.com/op/999" } });
      }
      if (url.includes("/op/999")) {
        return jsonResponse({ status: "failed", error: { code: "InvalidDocument" } });
      }
      throw new Error("unexpected");
    });
    vi.stubGlobal("fetch", fetchMock);
    const adapter = new DocumentIntelligenceAdapter({ endpoint: "https://di.example.com", apiKey: "key123", pollIntervalMs: 1 });
    await expect(adapter.analyzeDocument(Buffer.from("x"), "prebuilt-invoice")).rejects.toThrow(/failed/i);
  });

  it("throws when the analyze request itself errors (5xx)", async () => {
    const fetchMock = vi.fn(async (url: string) => {
      if (url.includes(":analyze")) return jsonResponse({}, { status: 500 });
      throw new Error("unexpected");
    });
    vi.stubGlobal("fetch", fetchMock);
    const adapter = new DocumentIntelligenceAdapter({ endpoint: "https://di.example.com", apiKey: "key123" });
    await expect(adapter.analyzeDocument(Buffer.from("x"), "prebuilt-invoice")).rejects.toThrow(/500/);
  });
});